Can a Blinded caster with Blindsight use spells that require them to see the target?

The situation I have in mind is the following:

An epic battle ensues between a Young Green Dragon (caster variant) and a Purple Worm. The Purple Worm swallows the dragon; meanwhile, the dragon has blindsight and can cast Command.

Command is a spell that requires you to see the target. However, the dragon is Blinded (so it can’t see) while swallowed. It has blindsight out to 30 ft, though, so it can perceive its surroundings without relying on sight.

Can the Young Green Dragon use the Command spell to have the Purple Worm retch it out?

The general question is: does the interaction of the Blinded condition with blindsight still prevent the caster from using spells that require them to see the target?


There is another question which asks if creatures with blindsight can be affected by the Blinded condition. The answer is yes, and we begin this question with the fact in mind that the caster is both Blinded and has blindsight.

Does the Arcane Archer’s Shadow Arrow inhibit blindsight, tremorsense, and/or truesight?

Shadow Arrow:

You weave illusion magic into your arrow, causing it to occlude your foe’s vision with shadows. The creature hit by the arrow takes an extra 2d6 psychic damage, and it must succeed on a Wisdom saving throw or be unable to see anything farther than 5 feet away until the start of your next turn.

Blindsight:

A creature with blindsight can perceive its surroundings without relying on sight, within a specific radius.

If a creature with blindsight (like a Flying Sword) fails its saving throw against an arcane archer’s Shadow Arrow, is its ability to perceive enemies via blindsight restricted? Would creatures with truesight or tremorsense be handled the same way?

It seems to me that this is fairly straightforward, but upon reading this question about opportunity attacks, there seem to be cases where the word "see" is used more generically as all forms of perception.

When an invisible character leaves a blindsight creature’s reach, does the creature get an Opportunity Attack?

A character in the party cast Invisibility on herself, making her invisible. She then tried to move past a Giant Spider, which has Blindsight 10 ft. Per “Does Blindsight detect Invisibility?” the Spider can still tell that the character was there, since the rules for Blindsight say “A monster with blindsight can perceive its surroundings without relying on sight”

But, as she leaves the Spider’s reach, does the Spider get an Opportunity Attack? Per the rules, “You can make an opportunity attack when a hostile creature that you can see moves out of your reach.”

Blindsight just says “can perceive”, but an Opportunity Attack requires “you can see”. Is the “perceiving” of Blindsight enough to be able to “see” for the purposes of the Opportunity Attack rule?

As the DM, I ruled “no” simply on the principle that “When in doubt, rule in favor of the players”, but I’m really not sure that’s right, as I may be taking things too literally.

Does a creature possessed by intellect devourer have blindsight?

The intellect devourer’s feature Body Thief says the following:

While inside a creature, the intellect devourer has total cover against attacks and other effects originating outside its host. The intellect devourer retains its Intelligence, Wisdom, and Charisma scores, as well as its understanding of Deep Speech, its telepathy, and its traits. It otherwise adopts the target’s statistics.

Does it retain its 60ft blindsight and immunity to the blinded condition while inside the creature?

Can a creature with blindsight see another creature that is Heavily Obscured?

If a creature is Heavily Obscured, can it be seen normally by a creature with blindsight? More specifically, will a creature with blindsight have disadvantage on attacks against the heavily obscured creature?

For example, say that a creature is Heavily Obscured by the effects of Fog Cloud or Shadow of Moil, can that creature be seen by a creature with blindsight?

Do crabs have blindsight out of water?

A wizard can choose a crab as a familiar, and crabs have a blindsight of 30ft and are amphibian.

I can understand why crabs would have blindsight in water, as they can notice movement in the water and (apparently) changing salt levels to detect enemies. But it makes no sense for a normal crab to have blindsight out of water.

But from a purely mechanical standpoint, nothing is stopping me from having a crab familiar, and get 30ft blindsight by sharing senses with my familiar. Essentially having a constant "detect invisibility" seems a bit strong though for a 1st lvl spell.

Thoughts?

5e: Does Blindsight detect a scrying sensor?

My party’s going to be encountering an Elder Oblex that’s gained more sentience than usual. The party has a mirror of Scrying (cast once per day without components/slots). They’re wanting to use said mirror to spy on the Oblex, get an idea where exactly it is, plan an ambush for it.

Elder Oblex has blindsight. Assuming the Oblex fails the save to resist the Scrying spell, would it notice the sensor created by the spell? The sensor is invisible, which would be ignored by the blindsight, but I’m not sure if the sensor does any other kind of sensory effect that could be detectable by blindsight.

The exact wording of Scrying is, “On a failed save, the spell creates an invisible sensor within 10 feet of the target. You can see and hear through the sensor as if you were there. The sensor moves with the target, remaining within 10 feet of it for the duration. A creature that can see invisible objects sees the sensor as a luminous orb about the size of your fist.”

Thanks in advance for any advice/insight!

In what way does Blindsight compliment Truesight?

While the definitions are quite clear,

Blindsight being:

A monster with blindsight can perceive its surroundings without relying on sight, within a specific radius.

Creatures without eyes, such as grimlocks and gray oozes, typically have this special sense, as do creatures with echolocation or heightened senses, such as bats and true dragons.

If a monster is naturally blind, it has a parenthetical note to this effect, indicating that the radius of its blindsight defines the maximum range of its perception.

and Truesight being:

A monster with truesight can, out to a specific range, see in normal and magical darkness, see invisible creatures and objects, automatically detect visual illusions and succeed on saving throws against them, and perceive the original form of a shapechanger or a creature that is transformed by magic. Furthermore, the monster can see into the Ethereal Plane within the same range.

it’s easy to see that they each have their own unique applications. However, there seems to be a range of overlapping between these senses when it comes to visual illusions that brings up many questions, mostly formated as:

Does Blindsight allow a creature to ____________ like Truesight does?

Eg.:

  • Does Blindsight allow a creature to see in normal and magical darkness?
  • Does Blindsight allow a creature to see invisible creatures and objects?
  • Does Blindsight allow a creature to automatically detect visual illusions and succeed of saving throws against them?

I apologize if this is a duplicate question, as I am sure it’s been asked before, but as I didn’t find it in the search, I thought it would be interesting to see the comparison between these two types of senses, focusing on what’s similar between them.